The present disclosure relates to a semiconductor device, and more specifically, a memory device employing a charge storage trench underlying a body region of a field effect transistor and a method manufacturing the same.
Trapped electrical charges in a body region of a field effect transistor alter the threshold voltage of the field effect transistor. Such a change in the threshold voltage in the field effect transistor can be detected by a sensing circuitry as known in the art to determine the charge state of the field effect transistor, i.e., the amount of electrical charges trapped in the body region of the field effect transistor. A challenge in such devices is the leakage current at the p-n junctions that are present between the body region and the source and drain regions of the field effect transistor. The greater the leakage current, the lesser the retention time for the trapped electrical charges, and consequently, the lesser the retention time for the stored information. Thus, a memory device with lesser leakage current through p-n junctions is desired.